a) Field of the Invention
The invention is directed to a device for aligning and coupling at least a partial region of a movable object to a destination, with interengaging fixed and movable coupling elements.
Such devices can be used, inter alia, for transport vehicles in semiconductor fabricating plants and by manufacturers for fitting out such fabricating plants, on which vehicles mechanisms for the highly accurate, reproducible and reliable transfer of items between the vehicle and the destination are installed.
The items may be, for example, transport containers for material transport; the destinations may be processing stations or depositing locations spatially removed from one another.
b) Description of the Related Art
In semiconductor fabricating plants, it is customary to transport the substrates to be processed in open or closed containers between different locations and different processing devices by transport devices specially designed for the purpose. In such cases, the handling of the containers during the required loading and unloading operations is to take place in an ergonomic way for the operating personnel. The latter is of special significance with the increasing size of substrates to be processed and the associated increase in size and weight of the containers.
Known simple transport vehicles have storage capabilities for the containers and require loading and unloading by the operating personnel. A solution which is as simple as possible is important particularly whenever a transport system has to be used as an interim solution for an automatic system, because the containers to be transported exceed the ergonomically admissible limit. Specifically in the early and medium-term construction phase of semiconductor fabricating plants, manually operated transport systems are required in order to optimize fitting out and work procedures. However, such interim solutions usually rule out fully automatic systems with complicated and expensive electronics and sensor systems, for reasons of cost. When such a transport vehicle has reached its destination, its adequately accurate positioning and fixing at the destination is required with respect to the loading and unloading station.
A known device according to U.S. Pat. No. 5,655,869 serves the purpose of coupling specially designed robot equipment to permanent fixtures. The device includes a mobile enclosure, which has aligning and holding elements for fastening on a coupling element aligned with respect to the permanent fixture. The coupling element is an adjustable bottom plate with a beveled front edge, in which semispherical-cap supporting screws are deposited in shaped elements for positive-locking orientation in accordance with coordinates. For fastening, a permanent magnet with reversible force is fitted in the enclosure. With such a device, a stable adjustment to the set coordinates is possible with respect to the permanent fixture. It is expressly provided that only for service purposes is the device to be removed from the permanent fixture and reproducibly brought back into place.
It is disadvantageous that the means for aligning and fixing allow only a single position at the destination. In this respect, the device is not suitable for a carriage in constant transport, owing to its inadequate flexibility. Restrictions, such as a relatively small available space, the location of which has to be predetermined, cause additional problems for the coupling elements.
In U.S. Application Ser. No. 08/979,522 there has already been described a manually guided vehicle which can be aligned and fixed in a number of positions with respect to a destination. Once the coupling state has been established for a position, a mechanism assigned to this position, with which a transfer of the containers takes place, is put into operation by the operating personnel. Since the status of the coupling and the operation of the mechanism are dependent on each other, it is desirable for reasons of reliability, safety and value of the work product if the operating personnel are prevented from taking operating steps which disturb the relationship between the status of the coupling and the operation of the mechanism.